Lazardâs role as financial adviser to Barclays has broken its UK deal record and raised eyebrows among its rivals.

The €59.7bn ($79.6bn) transaction beats its previous record for a UK advisory mandate, established last year when it worked on the £15bn (€22bn) sale of UK airports operator BAA to Spain’s Ferrovial.

Marcus Agius, former chairman of Lazard, was at the centre of both deals but not in his capacity as a Lazard banker. He was chairman of BAA when he sought Lazard’s advice on the deal. The bank received full league table credit but no fee.

Agius stepped down as chairman of Lazard’s UK operation at the end of last year and started work as chairman of Barclays on January 1. He is understood to retain a 1.2% stake in Lazard.

Rivals have suggested Lazard has been awarded the mandate because of Agius’ role as chairman of Barclays, which both companies refute. A Barclays spokesman said: “We have used Lazard as an adviser before.”

Lazard advised the bank on two private deals with undisclosed values – the acquisition of Indexchange last July and the purchase of Juniper Financial – now Barclaycard US – in December 2004. Lazard declined to comment. Agius is not short of experience on banking deals. In 2001 he advised Halifax on its acquisition of Bank of Scotland.

Lazard does not feature among the top fee earners from Barclays, according to data provider Dealogic. Barclays Capital earned 67% of total investment banking revenues paid by Barclays since 1998. Credit Suisse was the second-biggest fee earner with 9.1%.